only the right reorienting itself to its original position after having ceded so much ground to the left

The timeline is long enough that both this is true and for many people that "original position" was never in their lifetime so its fair to say it is a huge shift to them as well.

having fixed beliefs, is by nature static

This is something true in theory, but, like communism, manifests completely differently in reality. We can see just in this very forum that the Right is fractured among many different beliefs and even more so "what do we do with" type beliefs.

Whether that's pragmatic "we do what we need to do walk the path" beliefs, or genuinely breaking from the Right of old, we can hardly find two guys who agree on everything.

The Left doesn't have this problem because, as you said, they have no beliefs so they can just mind meld together, whereas the Right has to compromise together to stay a mass big enough to matter. In better times, we would be fighting among each other about whose belief is better but at the moment we have to bundle up to fight the horde that is the Left.